Turn on the shortcuts extension, then select "Configure Shortcuts" from the menu. Segfault.

I've had this problem with three Midoris, including 0.5.5 i586 1vl71.mTo get just a little more info, I slapped together a 0.5.1 with symbols from its SlackBuild. Obviously some things missing from my package, but the run was the same, and but for the additional info here (and the "missing" icons), the messages were equivalent.

Program received signal SIGSEGV, Segmentation fault.0xb7e6f41a in g_str_hash () from /usr/lib/libglib-2.0.so.0#0 0xb7e6f41a in g_str_hash () from /usr/lib/libglib-2.0.so.0#1 0xb7e6e988 in g_hash_table_lookup () from /usr/lib/libglib-2.0.so.0#2 0xb79bd080 in gtk_stock_lookup () from /usr/lib/libgtk-x11-2.0.so.0#3 0xb2769929 in shortcuts_label_for_action (action=0x8198558) at ../extensions/shortcuts.c:118#4 shortcuts_get_preferences_dialog (extension=0x8154af8) at ../extensions/shortcuts.c:228#5 shortcuts_menu_configure_shortcuts_activate_cb (extension=0x8154af8, menuitem=<optimized out>) at ../extensions/shortcuts.c:259#6 shortcuts_menu_configure_shortcuts_activate_cb (menuitem=0x82ffab0, extension=0x8154af8) at ../extensions/shortcuts.c:252#7 0xb7f77b4f in g_cclosure_marshal_VOID__VOID () from /usr/lib/libgobject-2.0.so.0#8 0xb7f75e66 in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0#9 0xb7f89bd7 in ?? () from /usr/lib/libgobject-2.0.so.0#10 0xb7f91feb in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0#11 0xb7f921f3 in g_signal_emit () from /usr/lib/libgobject-2.0.so.0#12 0xb7a52542 in gtk_widget_activate () from /usr/lib/libgtk-x11-2.0.so.0#13 0xb795b14d in gtk_menu_shell_activate_item () from /usr/lib/libgtk-x11-2.0.so.0#14 0xb795b4e9 in ?? () from /usr/lib/libgtk-x11-2.0.so.0#15 0xb79529e1 in ?? () from /usr/lib/libgtk-x11-2.0.so.0#16 0xb794932a in ?? () from /usr/lib/libgtk-x11-2.0.so.0#17 0xb7f74cdd in ?? () from /usr/lib/libgobject-2.0.so.0#18 0xb7f75e66 in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0#19 0xb7f89836 in ?? () from /usr/lib/libgobject-2.0.so.0#20 0xb7f916e1 in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0#21 0xb7f921f3 in g_signal_emit () from /usr/lib/libgobject-2.0.so.0#22 0xb7a505a3 in ?? () from /usr/lib/libgtk-x11-2.0.so.0#23 0xb7947b2c in gtk_propagate_event () from /usr/lib/libgtk-x11-2.0.so.0#24 0xb7947fd0 in gtk_main_do_event () from /usr/lib/libgtk-x11-2.0.so.0#25 0xb77e3288 in ?? () from /usr/lib/libgdk-x11-2.0.so.0#26 0xb7e7fc73 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0#27 0xb7e80010 in ?? () from /usr/lib/libglib-2.0.so.0#28 0xb7e804eb in g_main_loop_run () from /usr/lib/libglib-2.0.so.0#29 0xb7946e70 in gtk_main () from /usr/lib/libgtk-x11-2.0.so.0#30 0x08069595 in main (argc=1, argv=0xbffff2f4) at ../midori/main.c:418